1.

2.

3.

4.

5.

6.

7. $m=\frac{2}{9}$, y-intercept (0, 4)

8. $m=-\frac{3}{8}$, y-intercept (0, 5)

9. $m=-4$, y-intercept (0, −7)

10. $m=\frac{2}{7}$, y-intercept (0, −6)

11. $m=-4.2$, y-intercept $\left(0,\frac{3}{4}\right)$

12. $m=-4$, y-intercept $\left(0,-\frac{3}{2}\right)$

13. $m=\frac{2}{9}$, passes through (3, 7)

14. $m=-\frac{3}{8}$, passes through (5, 6)

15. $m=0$, passes through (−2, 8)

16. $m=-2$, passes through (−5, 1)

17. $m=-\frac{3}{5}$, passes through (−4, −1)

18. $m=\frac{2}{3}$, passes through (−4, −5)

19. Passes through (−1, 5) and (2, −4)

20. Passes through $\left(-3,\frac{1}{2}\right)$ and $\left(1,\frac{1}{2}\right)$

21. Passes through (7, 0) and (−1, 4)

22. Passes through (−3, 7) and (−1, −5)

23. Passes through (0, −6) and (3, −4)

24. Passes through (−5, 0) and $\left(0,\frac{4}{5}\right)$

25. Passes through (−4, 7.3) and (0, 7.3)

26. Passes through (−13, −5) and (0, 0)

27. (0, −3)

28. $\left(-\frac{1}{4},7\right)$

29. $\left(\frac{2}{11},-1\right)$

30. $(0.03,0)$

31. Find a linear function h given $h(1)=4$ and $h(-2)=13$. Then find $h(2)$.

32. Find a linear function g given $g\left(-\frac{1}{4}\right)=-6$ and $g(2)=3$. Then find $g(-3)$.

33. Find a linear function f given $f(5)=1$ and $f(-5)=-3$. Then find $f(0)$.

34. Find a linear function h given $h(-3)=3$ and $h(0)=2$. Then find $h(-6)$.

35. $\begin{array}{l}y=\frac{26}{3}x-11,\\ y=-\frac{3}{26}x-11\end{array}$

36. $\begin{array}{l}y=-3x+1,\\ y=-\frac{1}{3}x+1\end{array}$

37. $\begin{array}{l}y=\frac{2}{5}x-4\\ y=-\frac{2}{5}x+4\end{array}$

38. $\begin{array}{l}y=\frac{3}{2}x-8\\ y=8+1.5x\end{array}$

39. $\begin{array}{l}x+2y=5,\\ 2x+4y=8\end{array}$

40. $\begin{array}{l}2x-5y=-3,\\ 2x+5y=4\end{array}$

41. $\begin{array}{l}y=4x-5,\\ 4y=8-x\end{array}$

42. $\begin{array}{l}y=7-x,\\ y=x+3\end{array}$

43. (3, 5), $y=\frac{2}{7}x+1$

44. (−1, 6), $f(x)=2x+9$

45. (−7, 0), $y=-0.3x+4.3$

46. (−4, −5), $2x+y=-4$

47. (3, −2), $3x+4y=5$

48. (8, −2), $y=4.2(x-3)+1$

49. (3, −3), $x=-1$

50. (4, −5), $y=-1$

51. The lines $x=-3$ and $y=5$ are perpendicular.

52. The lines $y=2x-3$ and $y=-2x-3$ are perpendicular.

53. The lines $y=\frac{2}{5}x+4$ and $y=\frac{2}{5}x-4$ are parallel.

54. The intersection of the lines $y=2$ and $x=-\frac{3}{4}$ is $\left(-\frac{3}{4},2\right)$.

55. The lines $x=-1$ and $x=1$ are perpendicular.

56. The lines $2x+3y=4$ and $3x-2y=4$ are perpendicular.

57.

58.

59.

60.

61. Internet Use. The following table illustrates the growth in worldwide Internet use.

1. Model the data with a linear function. Let the independent variable represent the number of years after 2006; that is, the data points are $(0,1.093),(3,1.802)$, and so on. Answers may vary depending on the data points used.

2. Using the function found in part (a), estimate the number of world Internet users in 2017 and in 2020.

   Year, x	Number of World Internet Users, y (in billions)
   2006, 0	1.093
   2007, 1	1.319
   2008, 2	1.574
   2009, 3	1.802
   2010, 4	1.971
   2011, 5	2.267
   2012, 6	2.497
   2013, 7	2.749
   Source: Internet and Facebook World Stats

62. Cremations. The following table illustrates the upward trend in America to choose cremation.

1. Model the data with a linear function. Let the independent variable represent the number of years after 2005. Answers may vary depending on the data points used.

2. Using the function found in part (a), estimate the percentage of deaths followed by cremation in 2011 and in 2016.

   Year, x	Percentage of Deaths Followed by Cremation, y
   2005, 0	32.2%
   2006, 1	33.5
   2007, 2	34.3
   2008, 3	35.3
   2009, 4	36.7
   2010, 5	40.6
   Source: Cremation Association of North America

63. Electricity Use. Data on the average annual household use of electricity, in kilowatt-hours, are listed in the following table. Model the data with a linear function and predict the average annual household electricity use in 2019. Answers may vary depending on the data points used.

64. Median Household Income. Data on the median household income in the United States (adjusted for inflation) are listed in the following table. Model the data with a linear function, estimate the median household income in 2009, and predict the median household income in 2017. Answers may vary depending on the data points used.

65. Bottled Water. Data on the per-capita consumption, in gallons, of bottled water in the United States are given in the following table. Model the data with a linear function and predict the per-capita consumption of bottled water in 2017. Answers may vary depending on the data points used.

66. Accessing the Internet by Smartphone. Data on the percentage of adults who access the Internet by smartphone are given in the following table. Model the data with a linear function and predict the percentage of adults in 2016 who will access the Internet using a smartphone.